Memory is one type of integrated circuitry, and is used in computer systems for storing data. Integrated memory is usually fabricated in one or more arrays of individual memory cells. The memory cells are configured to retain or store memory in at least two different selectable states. In a binary system, the states are considered as either a “0” or a “1”. In other systems, at least some individual memory cells may be configured to store more than two levels or states of information.
An example memory device is a programmable metallization cell (PMC). Such may be alternatively referred to as a conductive bridging RAM (CBRAM), nanobridge memory, or electrolyte memory. A PMC may use ion conductive material (for instance, a suitable chalcogenide or any of various suitable oxides) sandwiched between a pair of current conductive electrodes, and such material may be referred to as “switching” material. A suitable voltage applied across the electrodes can generate current-conductive super-ionic clusters or conducting filaments. Such may result from ion transport through the ion conductive material which grows the clusters/filaments from one of the electrodes (the cathode) and through the ion conductive material. The clusters or filaments create current-conductive paths between the electrodes. An opposite voltage applied across the electrodes essentially reverses the process and thus removes the conductive paths. A PMC thus comprises a high resistance state (corresponding to the state lacking a conductive bridge extending through a switching material) and a low resistance state (corresponding to the state having a conductive bridge extending through a switching material), with such states being reversibly interchangeable with one another.
Although there has been some effort toward development of PMC devices, there remains a need for improved memory cells. Accordingly, it would be desirable to develop new memory cells.